Tube mill



J. S. BOND.

TUBE MILL.

FILED MAY 21, 1922.

Feb. 6, 1923.

2 SHEETS-SHEET I.

NTOR

and zn oRNEYS J J. S. BOND.

TUBE MILL.

FILED MAYZY, 1922.

Feb. 6, 1923.

2 SHEETS SHEET Z.

R O T W@ ATTQRNEM Patented Feb. 6, 1 923.

P A T I JOHN S. BOND, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO WORTHINGTON PUMP AND MACHINERY CORPORATION, A CORPORATION OF VIRGINIA.

TUB MILL.

Application filed May 27,

in grate screens for tube or ball mills and.

has for its object the provision of a cheap and efficient screen having interchangeable grate bars, and especially to provide a satisfactory partition for such mills divided into two or more compartments with balls ofdifferent sizes for successive coarse and fine grinding.

In such compartment mills the hammering of the heavy tumbling balls in the first compartment and the severe rubbing action on the screen, necessitates the screen metal about the openings being of special material that will not flow and thus not close or partially close the screen openings. In accordance'with the present invention, the screen openings are formed by grate bars made preferably of hardened steel, and a construction employing grate bars of equal length is provided, which is simple, durable, cheap, and convenient for repair and replacement of grate bars. While the invention is especially intended for partition screens in compartment mills, it is applicable, also, to inlet or discharge screens .in either compartmentor single chamber mills and for other similar uses.

For a full understanding of the invention, a detailed description of a tube mill and screens embodying all the features of the invention in the preferred form, will now be given in connection with the accompanying drawings and the features forming the invention then specifically pointed out in the claims. V

In the drawings Figure l is a central vertical section of a tube or ball mill;

Figure 2 is a section on line 2-2 of Figure 1; 4

Figure 3 is an enlarged section on line 3-3 of Figure 2; Figure 4: is a view similar to,Figure 2, showing a modified form; and-if 1922. Serial No. 564,198.

' vFigure 5 is an enlarged section on line 5--5 of Figure 4.

Referring to the drawings, represents a cylindrical drum orthe like closed at its ends by feed and discharge heads-21, 22, cast integrally with feed and discharge gudgeons, respectively 23, 24 by which drum 20 is supported for rotation by a spur gear wheel 25 actuated in any well known manner. The mill shown by way of illustration is of the compartment type comprising a coarse grinding compartment 26 and a fine grinding compartment 27, separated by a suitable grate partition denoted generally by A. The compartment 27 is separated from discharge gudgeon 24 by a screen 28 spaced from the discharge head 22 by lifters- 29, forming radial passages for the discharge of the ground product. 'As is usual, the interior of the drum is protected by suitable liners 30 of forged steel or the like and manholes 31 are provided for access to the interior of the drum.

In operation, material fed to compartment 26 through feed gudgeon 23 is coarsely ground by the large balls shown therein and passes through screen A to compartment 27 for fine grinding by the small balls therein.

The product then passes through screen 28 to the radial passages formed by lifters 29, for delivery to the discharge gudgeon 24:, from which it passes to suitable collection means (not shown).

Screen A, which forms the subject matter of the present invention, as shown in Figures 2 and 3, comprises a frame 1, provided with an annular flange 2 secured to the drum 20 in any suitable manner, as by rivets 3. The frame 1 is reinforcedby suitabie. plates forming radial lifters 4 on the back of the frame 1 within the annular flange 2, which form with plate 5,'preferably divided into sectors, radial passages connecting with a central port 6 in the plate 5. Frame 1 has an opening corresponding to the port 6 and is suitably recessed thereabout for the reception of discharge cone 7 provided with ribs or lifters 8, which register with the ends of the lifters 4; Suitable openings 9, rectangular or approximately rectangular in form, are provided in the frame l across which extend grate bars 10 of uniform length and provided with shouldered .ends 11, which are locked against the frame 1 by suitably recessed locking bars 12, which may be secured to frame 1 by bolts 13 as shown. At the ends of the grate bar groups and on the two unsecured sldes, I provide suitable filler plates 14, which are bolted to the frame 1, the grate bars 10, looking bars 12 and filler plates 14 being preferably of the same thickness so as to form a flush surface. The cen tral filler plate 14" extends across the back of the discharge cone 7 andis preferably sc cured to the plate 5 bybolts 15, asshown.

In the modification shown in Figures 4 and 5, the frame a is preferably formed in a plurality of sections, each section extending across the drum 20 and provided each with a single rectangular opening 6. The uniform length grate bars 0 are provided with central tongues d of the same thickness as the frame a and are of such length as to fit within the openings 6. The grate bars 0 are held on one side of the frame a by locking bars e and filler plates f and on the opposite side by reinforclng plates 9 correspond ing in shape to bars 6' and plates 7. Each section of the frame a, its bars 6, plates f and g, and grate bars 0 are secured together by bolts h, and are preferably of such thick ness as to form flush surfaces on both sides of the frame. The sections of the screen thus formed are secured by bolts 71 to an annular angle plate which may to the drum 20.

It will be understood that the invention is not to be limited to the specific form shown and described, as many modifications may be made within the invention as defined by the claims.

What is claimed is:

1. A ball mill or the like having a transverse grate screen comprising a frame having a plurality of approximately rectangular openings, grate bars of uniform length extending across each opening, locking bars secured to the frames for locking the grate bars-in position, and filler plates secured on the uncovered portion of the frame.

2. A ball mill or the like having a transverse grate screen comprising a frame having a plurality of approximately rectangular openings, grate bars of uniform length extending across each opening, locking bars secured to the frame for locking the grate bars in position, and filler plates secured on the uncovered portion of the frame, the grate bars, locking bars and filler plates forming a flush surface.

3. A ball mill or the-like having a transverse grate screen comprising a sectional be riveted or bolted frame having a plurality of approximately rectangular openings, grate bars of uniform length extending across each opening, looking bars secured to the frame for locking the grate bars in position, andfiller plates secured on the uncovered portion of the frame.

4. A ball mill or the like having a transverse grate screen comprising a sectional frame having a rectangular opening in each section thereof, grate bars of uniform length extending across each opening, lock: ing bars secured to the frame for locking the grate bars in position, and filler plates secured on the uncovered portion of the frame. L I

A ball mill or the like having a, transverse grate screen comprising a frame having a plurality of approximately rectangular openings, grate bars extending across each opening, locking-bars secured to the frame for locking the grate bars in position, filler plates secured on the uncovered port-ion of the frame, and reinforcing plates secured on the opposite side of the frame.

6. A ball mill or the like having a transverse grate screen comprising a sectional frame having a rectangular opening in each section thereof, grate bars extending across each opening, locking bars secured to the frame for locking the grate bars in position, filler plates secured on the uncovered portion of the frame, and reinforcing plates secured on the opposite side of the frame.

7 A ball mill or the like having a transverse grate screen comprising 'a sectional frame having a rectangular opening in each section thereof, grate bars of uniform length 4 extending across each opening, locking bars 8. A ball mill or the like having a trans- I verse grate screen comprising a frame having a plurality of openings, grate bars of uniform length extending across each opening, locking bars secured to the frame for locking the grate bars in position, and filler plates secured on the uncovered portion of the frame.

9. ball mill or the like having a transverse grate screen comprising a sectional frame having an opening in each section, grate bars of uniform length extending across each opening and locking bars secured to the frame for locking the grate bars in position.

10. A ball mill or the like having a transverse grate screen comprising a frame having a plurality of approximately rectangular openings, grate bars of uniform length extending across each opening, and locking bars secured to the frame for locking the grate bars in position.

11. A partition screen for ball mills or the like comprising a frame having a plurality of openings, grate bars of uniform length extending across each opening, locking bars secured to the frame for locking the bars in llu position, filler plates secured to the uncovered portion of the frame, and reinforcing plates secured on the opposite side'of the .frame.

ing the grate bars in position, filler plates secured on thetuncovered portion, and reinforclng plates secured on the opposite side of the frame.

l3.'A grate screen for ball mills or the. like comprising sectional frame at having 15 openings b, grate bars 0 within the openings,

tongues d on grate bars '0, bars a and plates? secured on one side of frame a and extending over openings 6 and tongues d, and plates 9 securedon the opposite side of frame a and 20 .extending-oyer openings 6 and tongues d,

for securing grate bars cytlie frame a, plates 7 and g, and bars 0 forming flush surfaces.

In testimony whereof, I have hereunto set my hand.

v JOHN S. BOND. 

